1# ArkUI_ContextCallback 2 3 4## Overview 5 6Event type. 7 8**Since**: 12 9 10**Related module**: [ArkUI_NativeModule](_ark_u_i___native_module.md) 11 12**Header file**: [native_type.h](native__type_8h.md) 13 14## Summary 15 16 17### Member Variables 18 19| Name| Description| 20| -------- | -------- | 21| void \* [userData](#userdata) | Custom type. | 22| void(\* [callback](#callback) )(void \*[userData](#userdata)) | Event callback. | 23 24 25## Member Variable Description 26 27 28### callback 29 30``` 31void(* ArkUI_ContextCallback::callback) (void *userData) 32``` 33**Description** 34 35Event callback. 36 37 38### userData 39 40``` 41void* ArkUI_ContextCallback::userData 42``` 43**Description** 44 45Custom type. 46